<!DOCTYPE html>
<html reftest-async-scroll>
<style>
body {
  position: fixed;
  margin: 0px;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
}
#scrollbox {
  width: 100%;
  height: 100%;
  overflow: hidden;
}
#scrolledContents {
  height: 10000px;
  background: radial-gradient(circle, blue 30%, transparent 0);
  background-size: 80px 80px;
}
</style>
<body>
  <div id="scrollbox"
       reftest-dislayport-x="0" reftest-displayport-y="0"
       reftest-displayport-w="800" reftest-displayport-h="2000"
       reftest-async-scroll-x="0" reftest-async-scroll-y="20">
    <div id="scrolledContents"></div>
  </div>
</body>
</html>
